Improvement in hoisting apparatus



/mf fffrmm//Zym @am GEKW C@ AM. PHC-TD'LI' HG. C0. NY, (USBURN E'SPRGCESS) UNITED STATES PATENT VILLIAM SMITH, OF PHILADELPHIA,PENNSYLVANIA.

IMPROVEMENT IN HOISTING APPARATUS.

Specification forming part oi' Letters Pat-ent No. d495, dated November1, 1864.

To all whom it may concernl fv Be it known that I, WILLIAM SMITH, ofPhiladelphia, Pennsylvania, have invented an Improvement in HoistingApparatus 5 and I do hereby declare the following to be a full, clear,and exact description ot' the same, reference being had to theaccompanying drawings, and to the letters ot' reference marked thereon.

My invention consists in the use in hoisting apparatus of anintermediate shaft with a pinion operated from a driving-shaft by a wormand worin-wheel, in combination with a cog-wheel on the hoisting-drum ordrinnshaft, as described hereinafter, so that the hoisting apparatus maybe of limited dimensions, and not require the use of braking devices toresist the tendency ofthe drum to turn back in hoisting heavy weights.

In order to enable others to make and use my invention, I will nowproceed to describe its construction and operation.

0n reference to the accompan yingdrawin gs, Figure l is an end view ofmy improved hoisting apparatus, and Fig. 2 a plan view.

The frame-work or foundation of my improved hoisting apparatus iscomposed in the present instance ot' the two side pieces, A a 1d Af, twoend pieces, B and B', and the intermediate cross-piece, O. I) is thedrum forv receivin g the hoisting rope or chain,and is secured to ashaft, E, which turns at one end in the standard F, secured to thecross-piece C oi' the frame, and at the other end in a box or standardF, secured to the end piece, B, ot' the frame, a cog-wheel, Gr, beingsecured to the same shaft near one end ot' the drum. Into this wheel Ggears a pinion, H, on the shaft I, which turns at one end in the frameF', and at the opposite end in a suitable bearing, a, secured to oneside of a box, J, which is attached to or forms a part of the frame.Nithin this boX is a wormwheel, K, which is secured to the shaft I, andinto this wheel gears a worm, L, on the shaft M, one end ot which turnsin the end of the box, the other end turning in a suitable bearing, on.,on the frame. On this shaft are the two loose pulleys P and P and theintermediate fast pulley N, two driving-belts--one straight and theother crossed-bring used in connection with these pulleys in the samemanner and for the same purpose of obtaining a reverse motion as similarbelts are used in connection with turning-lathes, planing-machines, &c.

The drums of hoisting-machines have been heretofore operated through themedium ot' worm and worin-wheels, but in all cases the drum has beensecured directly to the shaft to which the worm is attached. There areto serious objections to this the ordinary arrangement oi' gearing forhoisting apparatus: First, it is necessary either to make the drum ot'smaller diameter, or else to increase the dia-meter of the worm-wheel toan extent which renders it unweildy in order to obtain the desiredpower; second, a heavy weight suspended to the hoisting rope or chain isapt to run down when not required, the worm and wheel being insuticientto resist this tendency of the weight to descend; hence it becomesnecessary to use some braking apparatus to assist the worm and wheel inresisting the downward tendency of the weight. It is true that byreducing the drum in diameter or by increasing the diameter ot' theworm-wheel this diticnity might'be in a measure obviated', but there arepalpable objections to both of these modes of remedying the evil. If itbe determined to increase the diameter of the worm-wheel, the increasemust be of such an extent as to render it unweildy and not convenientfor adaptation to localities in which the hoisting apparatus has to besituated, and if the drum be decreased in diameter the rope will beinjured by short bends, and it will be necessary to make the drum ofadditional length to take up the desired amount of rope. By the use ot'a pinion, H, on the worm-wheel shaft, and by causing this pinion to gearinto the wheel G or the drum, or drum-shaft, as described, all thesedifficulties may be obviated. The wheel and pinion aliord a leverageproportionate to their rcspective diameters, which le\erage actsdirectly to resist the tendency of a weight to turn the drum 5 hencethere is no necessity ot' employing complex and costly brakingapparatus. At the same time the drum may be of large diameter anddiminished length, the

worm-wheel K being also small in diameter, and in fact the Wholeapparatus may be of the desirable limited dimensions.

I claim as my invention and desire to secure by Letters Patent- The use,in hoisting apparatus, of the intermediate shaft, I, with its pinion H,operated from the driving-shaft by a Worm and wormwheel, in combinationwith the oog-wheel Gr on the hoisting-drum or drunishaft.

In testimony whereof I have signed my name to this speoitication in thepresence of two subscribing witnesses.

Titnessesz HENRY HoWsoN7 JOHN WHITE.

WM. SMITH.

